1. Field of the Invention
The present invention relates to an improvement on a camera or a like apparatus having a device for opening and closing the cover of a film cartridge chamber provided in the camera or the like.
2. Description of Related Art
Some of cameras commercialized during recently years are arranged such that, when a film cartridge in which a whole film including its fore end part, i.e., a leader part, is completely wound within there is loaded in a film cartridge chamber, a fork is driven to cause the film to be pulled out from the film cartridge and taken up and wound around on a spool shaft of the camera.
A problem with the camera of this kind lies in that, if the cover of the cartridge chamber is inadvertently opened by the user while the film is in process of being pulled out from the film cartridge within the cartridge chamber, the film would be exposed to light. To solve this problem, various devices has been developed. For example, In a camera disclosed in Japanese Laid-Open Patent Application No. HEI 8-286245, a lock member is provided in a part of a film transport gear train for locking the cover of the cartridge chamber. The lock member is arranged to be kept in a lock position to make the cover of the cartridge chamber unopenable by preventing an opening operation on a knob provided for opening and closing the cartridge chamber, when the film is in process of being wound and rewound.
In the case of this camera, however, the lock member is in an unlocking position for the opening-and-closing knob while the rotating direction of a film transport motor is in process of being changed from a film winding direction over to a film rewinding direction. Therefore, at the time of this change-over, the opening-and-closing knob might happen to be inadvertently operated to open the cover of the cartridge chamber. In view of this shortcoming, in U.S. patent application No. 09/105,755 (Japanese patent application No. HEI 9-/190789), there is disclosed a device as an improvement on the camera of this kind, in which the cover of the cartridge chamber is arranged to be not openable without performing a film winding action and a film rewinding action respectively once and, after that, to become openable by rotation in the film feeding or winding direction (hereinafter sometimes referred to as the thrust direction).
Meanwhile, with a camera arranged to use a film cartridge of the kind having a data disk, when the camera is loaded with the film cartridge, the camera performs a reading action to read data provided on the data disk by rotating a film winding spool of the film cartridge in the film rewinding direction before the above-stated driving in the thrust direction (thrust driving).
Therefore, in a case where a film cartridge of this kind is to be used for the camera which is provided with the above-stated improvement disclosed in U.S. patent application No. 09/105,744, it has been impossible to read data from the data disk, because the film winding action and the film rewinding action are arranged to be performed respectively once before opening the cartridge chamber cover by the thrust driving. More specifically, it has been impossible to read the data because the cartridge chamber cover would be opened if the thrust driving is performed after data reading from the data disk.
It is a first object of the invention to provide an apparatus having a device for opening and closing a film cartridge chamber cover arranged such that, as long as an opening operation member for the cartridge chamber cover is not operated, the cartridge chamber cover can not be opened even if a film winding spool of the film cartridge or a fork gear is caused to rotated forward or backward. In other words, the cartridge chamber cover is arranged to be openable only by operating the opening operation member.
Therefore, data can be read from the data disk by rotating the film winding spool in the direction of film rewinding before the thrust driving. Besides, in a case where the camera is loaded with a film cartridge which is used halfway, an unexposed frame can be searched out and then the film can be temporarily rewound to set the unexposed frame again at an exposure (aperture) position.
It is a second object of the invention to provide an apparatus having a cartridge chamber cover opening-and-closing device which is capable of preventing the setting of the film using state obtained at the end of rewinding from being varied by an unlocking action on the cartridge chamber cover.
It is a third object of the invention to provide an apparatus having a cartridge chamber cover opening-and-closing device which is capable of bringing a revolving member back to its standby position even under an irrational condition such as having an opening operation member for the cartridge chamber cover left inadvertently in an operated state, so that a film rewinding action can be carried out even under such an irrational condition.
To attain the above objects, in accordance with an aspect of the invention, there is provided a device for opening and closing a cover of a film cartridge chamber, comprising a gear member (11) having a gear part arranged to rotate for feeding and rewinding a film by engaging a supply spool of a film cartridge, a revolving member (12) arranged to engage the gear part and to be caused to revolve by rotation of the gear member, an opening operation member (7) provided for opening the cover, and a lock member (2, 3 and 5) arranged to lock the cover in a closed state or to unlock the cover, wherein the lock member moves from outside of a revolving travel locus of the revolving member to inside of the revolving travel locus of the revolving member in association with an operation of the opening operation member, and the lock member is driven by a revolving motion of the revolving member to unlock the cover. When the opening operation member is not operated, the lock member is located outside of the revolving travel locus. With the lock member at this position, therefore, the cover of the film cartridge chamber is never caused to open by film feeding (transport) and rewinding actions.
The device according to the invention further comprises a detection switch for detecting an operation position, for opening the cover, of the opening operation member, and a motor for driving and causing the gear part to rotate, wherein the motor causes the gear part to rotate when the opening operation member has been detected by the detection switch to be at the operation position.
In the device, the motor is arranged to rotate the gear part in the direction of feeding the film.
The device according to the invention further comprises a first detection switch arranged to detect whether or not the lock member is at an unlocking position, a second detection switch arranged to detect presence or absence of the film, and a motor provided for driving the gear part to rotate, wherein the motor drives the gear part to rotate in the direction of rewinding the film when the lock member has been detected by the first detection switch to be at a locking position and the film has been detected by the second detection switch to be absent.
The device further comprises an urging member arranged to urge the lock member to move toward a locking position thereof.
The device further comprises first and second restricting members arranged to define a movable range of the revolving member, and the revolving member is allowed to move within the movable range.
These and further objects and features of the invention will become apparent from the following detailed description of a preferred embodiment thereof taken in connection with the accompanying drawings.